The disclosure relates to a device for energy supply for trains, and in particular in the form of a gas-driven electric power generator carriage.
Hybrid operation of locomotives by gas is known from US 2002174796 A1, US 2009293759 A1, WO 2008073353 A2 and US 2005279242 A1.
US 2002174796 A1 discloses an energy tender vehicle for use in connection with a hybrid energy locomotive system having energy storage and recovery system. The energy storage and recovery system captures dynamic braking energy, excess energy from the engine, as well as externally supplied energy in one or more energy storage subsystems comprising; a flywheel, a battery, an ultra-capacitor, or a combination of such subsystems. In one embodiment, the energy storage and recovery system are located in an energy tender vehicle. The energy tender vehicle is equipped with optional traction motors. In one embodiment, the tender vehicle is configured to operate without any energy connections to the locomotive. An energy management system responds to energy storage and energy transfer parameters comprising data indicating current and upcoming rail profile information, to determine the present and future electrical energy storage and delivery needs. The energy management system controls accordingly storage and recovery of energy.
US 2009293759 A1 describes hybrid versions of diesel-electric locomotives and improves known technology by placing batteries in standard containers for intermodal transport that can be easily moved with easily accessible cranes built to move cargo containers. The containers are housing standard batteries so that different operators can use them through purchase or rental. This will provide several benefits: 1) after descent from altitude, a fully charged battery unit is removed from the train and put in a stock to reduce the weight of the train unless additional energy is needed for the further journey. For especially long descents, full battery units can be replaced with empty ones, repeatedly, to enable more energy capture as the train continues its descent. (2) Conversely, a train that runs upwards can be loaded with one or more full battery containers from a warehouse to reduce the use of fossil fuels during the ascent and if the need is there, receive replacement units along the trail when the original set does not last long enough to reach the highest point. (3) Various configurations are possible, such as two containers on top of each other to adapt to different needs. (4) Commercial trade with battery containers, made possible through standardization, will create a market for energy which will result in its most efficient use.
WO 2008073353 A2 discloses a hybrid propulsion system comprising a drive engine, a drive system, an energy storage system, a regenerative braking system and a control system applicable for controlling the drive engine, driving, energy storage and regenerative braking systems. Control systems receive input for geographical location, speed and terrain features, and handles energy discharge and energy charge operations.
US 2005279242 A1 describes a hybrid locomotive that can operate in a plurality of operating modes, extensive “slug” operating mode, an energy storage operating mode, a B-locomotive operating mode, five independent operating modes, as well as a source of energy operating mode, and/or can supply electric energy to an external power grid.
Gas operation of locomotives is known from US 2008121136 A1 and U.S. Pat. No. 6,308,639 B1, and the hybrid operation of gas-powered buses is well known.
US 2008121136 A1 describes a hybrid locomotive that includes at least one traction motor connected to at least one of a plurality of shafts and configured to engage at least one shaft. A power conversion system is connected to a main engine, and configured to supply electrical energy to the at least one traction motor and a second energy storage device. A fuel storage device is connected to the engine and configured to supply the main engine with gas fuel. The main engine is adapted to burn gas fuel to reduce emissions, while maintaining excellent power outlet characteristics, which may be supplemented by other sources of energy.
U.S. Pat. No. 6,308,639 B1 describes a switching unit which combines battery storage with a gas microturbine generator to provide a fuel efficient and environmentally friendly locomotive.
Hybrid operation with diesel is known from U.S. Pat. No. 5,129,328 A and U.S. Pat. No. 4,900,944 A, and that separate diesel-driven generator tender carriages for supplying electric train power are known.
U.S. Pat. No. 5,129,328 A discloses a gas turbine powered locomotive, in which a gas turbine is mounted on a locomotive frame. A high-speed alternator is directly connected to said gas turbine. Traction motors are connected by means of an energy control unit for controlling the engine load to the generator for driving a plurality of shafts of the locomotive. Gas storage containers are located on the locomotive frame.
US 2002117857 A1 discloses an electrical energy storage and regeneration system, which uses the electricity generated by dynamic braking of a diesel-electric locomotive to convert water into hydrogen and oxygen gases through hydrogen electrolysis. The gases are compressed, cooled and stored in tanks for later use for supply to fuel cells. Electricity generated by an electrochemical reaction in the fuel cells is used to power the locomotive traction motors. Alternatively, the regenerated electricity is used to supplementing local or regional energy supply. The system can be arranged in a carriage which can be connected directly to a locomotive.
U.S. Pat. No. 4,900,944 A describes a supplementary motor (booster unit) for diesel-electric locomotives that has a frame mounted diesel engine, a generator and several traction motors connected to said generator. A gas turbine is mounted on the frame adjacent to the diesel engine, a high-speed alternator is directly connected to the turbine and various rectifiers coupled to the output of the high-speed alternator. The alternator is adapted to control the output power thereof. The high-speed alternator is connected in parallel with the main train generator, so that the traction motors can be supplied with additional electrical energy when needed.
US 2008223250 A1 discloses a locomotive for passenger transport which captures and stores excess electric energy generated during dynamic braking of the locomotive. This excess energy is converted into energy for use on connected passenger railcars. In cases where the amount of captured energy is too low to meet the demand, the system is supplied with extra energy from the drive engine of the locomotive.
A diesel-electric locomotive has a generator powered by a large diesel engine. This generator operates electric traction motors which facilitate propulsion. The generator may also supply electric power to attached train carriages. Traction motors are also used as braking motors, where they generate electricity when braking—so-called dynamic braking. For ordinary diesel-electric locomotives the power generated from the dynamic breaking is conveyed to large electrical resistors, where the braking power is converted to heat that is wasted.
A hybrid locomotive stores this dynamic braking energy in batteries and reuses it to drive the traction motors in a transition phase before the main generator takes over. There is evidence that this technology can provide savings in fuel consumption in the range of 15 to 20% compared to ordinary diesel-electric drive (U.S. Pat. No. 5,129,328 A). The savings arise by capturing energy which is otherwise lost and by smoothing/equalizing energy consumption by supplying this to the operation of the battery bank.
A disadvantage of the prior art is that since it uses a large diesel generator (non-renewable energy), this will result in substantial energy and disproportionately large emissions of soot and greenhouse gases such as CO2 and NOx during idling and at slow speed.
Accordingly, there is a need to provide a device for energy supply of trains comprising a gas driven electric power generator arranged for providing energy for supply of electric power to the train/idle current to the train set.
There is further a need to provide a device for energy supply of trains comprising a gas driven electric power generator, which in combination with hybrid operation can be used to achieve significant environmental benefits in combination with diesel/gas/hybrid operation.
There is further a need to provide a device for energy supply of trains comprising a gas driven electric power generator which in combination with the locomotive's main engine/generator is used to achieve an optimized energy smoothing and hence reduced energy consumption during operation of the locomotive and the train set.